More than 18 months after the Environmental Protection Agency first approved the idea , a gas station west of Kansas City has begun selling E15, a fuel blend that is 15 percent ethanol instead of the 10 percent blend that is now standard in most of the country. The Phillips 66 brand station on Route 10 in Lawrence, Kan., uses “blender pumps” that allow the customer to choose a gasoline-ethanol mix that is 10 percent, 15 percent, 30 percent or 85 percent ethanol. Technically, the 15 percent blend was already available to drivers of “flex fuel” cars that can burn mixtures of up to 85 percent, but that is a tiny slice of the automotive fleet. The Kansas station is the first to offer E15 for regular cars. The E.P.A. has approved the use of E15 fuel in cars of the model year 2001 or later. Automakers say they are not convinced that the fuel is entirely safe for engines and warn...